The present invention relates to a regulator for diving and more particularly to such a regulator suitable to be used as a regulator usually referred to as a second stage.
A regulator for diving is well known, which comprises a basic structure adapted to be kept in air-tight condition so long as a diver is using it, a built-in pressure-controllable air supply mechanism provided in the basic structure, a mouthpiece connected to the basic structure and a check valve mounted on the basic structure so as to be switched between its opened and closed positions. An example of the air supply mechanism comprises a pressure control knob, a screw member adapted to be rotated as the knob is rotated and a slider in thread-engagement with the screw member. The slider moves forward or backward with respect to an axial direction of the screw member as the latter is rotated. This slider is pressed against a coil spring biasing the check valve in an axial direction of this coil spring so that the coil spring may be compressed or relaxed as the slider moves forward or backward. In this manner, a pressure of the air supplied from the air supply mechanism to the diver can be regulated.
With such a regulator of prior art, the air pressure can be regulated by rotating the knob since the knob can be rotated by a plurality of turns. However, such regulator of well known art makes it difficult, depending on the diver, to identify a level at which the air pressure is set by his or her own regulator. Furthermore, if the knob must be rotated by a plurality of turns in order to obtain a desired pressure level, operation of air pressure regulation is troublesome for the diver.
It is an object of the present invention to improve a regulator for diving so that somewhat troublesome knob manipulation required by the conventional regulator can be alleviated and a desired pressure level can be quickly set.
According to the present invention, there is provided a regulator for diving comprising a basic structure adapted to be kept in substantially air-tight installed so long as a diver is actually using it, a pressure-controllable air supply mechanism installed in the basic structure, a mouthpiece connected to the basic structure and a check valve attached to the basic structure so as to be operated between opened and closed positions.
The air supply mechanism further comprises a tubular housing connected to an air supply source lying outside the basic structure and a tubular joint member adapted to be joined to the housing within the basic structure in an axial direction of the housing and extending outwardly beyond the basic structure. There are provided in the axial direction of the housing, inside the housing and joint member, a pressure reducing valve member acting upon the air flowing from the supply source into the housing, a coil spring having one end acting upon a rear side of the valve member and a pressure regulating means acting upon the other end of the coil spring opposed to the one end so as to compress or relax the coil spring, and a pressure regulating means comprises a screw member extending in the axial direction of the housing and mounted on the joint member so as to be rotatable around the axis, the screw member having an inner end extending into the housing and an outer end extending outwardly from the housing, the inner end being formed with multiple threads, a slider mounted within the joint member in a manner that the slider can move slidingly in the axial direction of the housing but can not rotate around the axis and is operatively thread-engaged with the multiple thread screw. An inner end of the slider contacts with the opposite end of the coil spring and outside the basic structure is formed a knob adapted to rotate the screw member on the outer end of the screw member.
The present invention includes several preferred embodiments as follows:
The multiple thread screw is of a type having 2-4 threads and a lead of this multiple thread screw is formed so that approximately a single turn of the screw member may cause the slider to depress the coil spring from a maximum compressed condition to a minimum compressed condition.
The knob is provided with a ratchet mechanism adapted to control a rotational angle of the knob.
The ratchet mechanism comprises a concave-convex shaped member interposed between a region of the basic structure opposing to the knob and the knob and a spring means adapted to be selectively engaged with or disengaged from the concave-convex shaped member.